Pearl shells, known as riji or jakuli in the Bardi language, are associated with water, spiritual powers and healing due to the luminous shimmering quality of their surfaces. Bardi equate the light reflecting off the shells to lightning flashes, which are prominent during the monsoon, and to lights flashing off the cheeks of the Rainbow Serpent, who is closely linked to water and rain.

The tradition of interlocking designs etched into the surfaces of pearl shells is distinctive in Aboriginal art. The incised designs are highlighted with a mixture of ochre and resin, which is rubbed into the grooves. Decorated and plain pearl shells are used for rain-making and magical purposes, for trade, in ceremonies and as personal adornments such as necklaces or pubic covers when they are worn attached by belts or necklaces of hairstring.

Riji originate around Broome, in the west Kimberley region. They are objects of great value and have been exchanged along ancient trade routes over vast areas of the continent. They appear as far afield as Yuendumu in the desert, south-eastern Arnhem Land, Queensland and South Australia. Often plain pearl shells are decorated further along trade routes, far from their place of origin.